Alighting means for lighter-than-air ships



Jan. 22, 1929.

W. V. N. POWELSON ET AL ALIGHTING MEANS FOR LIGHTER-THAN-AIR SHIPS FiledSept. 6, 1921 BY. 7% M Patented Jan. 22,1929.

ATENT or FICE.

WILFRID V. N. EOW'ELSON AND VIAEEEN TRAVELL, OF NEW YORK, N. Y.

ALIGHTING Means res menses-marinara SHIPS. 1

Application filed September 6, 1921. Serial no. 498,607.

This invention relates to improvements in alighting means forlighter-than-air ships. Up to the present time, airships of large sizehave never been brought safely to rest on land or ater without theassistance of a large number of attendants. It is an object of thisinvention to provide means whereby an. airship may safely alight oneither land or water and without the assistance of any attendantwl'iatever. l

Airplanes have been commonly equipped with wheels for running on theground but if an airship were equipped with the same type of wheels andwheel attachments as those used on airplanes, there would result, onlanding, stresses which would distort or destroy the structure of theairship. lVe have invented ameans in connection with the use of landingwheels whereby the weight of the airship is distributed among severalwheels, regardless of unevenesses of the surface of the ground andwhereby the stresses produced inth'e structure of the airship, due toits weight being supported by these wheels, are kept withinpredetermined limits.

We also apply the same means or a modification thereof to permit thesafe alighting of an airship on the surface of a body of water and forthe prevention of the destruction of the airship due to wave actionwhile the airship is floating on water.

Also, our invention provides improved means for withdrawing thealighting wheels within the envelope of the airship during flight. iThese several objects are attained in our improvement by attachingwheels to an airship along the lower part thereof, by means of armswhich are pivotally connected to the airship. Pockets are provided inthe exterior envelope, into which these wheels with their supportingarms may be withdrawn during flight Previous to alighting, the wheelsare let down, the arms being provided with limit stops which prevent thewheels from being lowered too far. The wheels are held in this loweredposition by means of a spring, or other device, exerting anapproximately constant force, predetermined in amount. The structure ofthe airship may be designed to transmit different loads to differentwheels when resting or running on ground or water. Assuming that thedesign such that the wheels are to take approxibately equal loads, whenthe airship alights on an uneven surface of ground, the wheels vwill beraised to different elevations by the unevenness of the ground, but eachwheel will carry no more than its own proportion of the weight of theairship, producing in the airship structure no more than thepredetermined stresses. lt should be noted that even a large airship onalighting may have a weight only slightly in excess of the Weight of theair displaced thereby and that the actual load to be carried by eachwheel may be no greater than the load which is carried by a landingwheel of a much smaller airplane receiving no support fromlighterthan-air gas.

Such wheels may be used on an airship not only for alighting, but may beused in con nection with airships, heavier-tl1an-air and equipped withlifting planes, to run along the ground and thus obtain proper speed, sothat the lifting planes at such speed may raise the airship from theground. This method of launching an airship permits the loading of theairship beyond the lifting power of its gas and enables an airship of agiven size to carry a much greater load either of fuel or cargo than itcould otherwise carry. Such an advantage alone is of prime importance inthe successful financial operation of a commercial line ofairships.

For alighting on water and supporting the unbalanced weight of anairship thereon, the

wheels may be of larger size and fitted with water-tight air chambers,thereby providing a buoyancy for each wheel equal to or 1n excess of theload which it is designed tocarry.

These wheels may have their outside rims adapted for running on theground, so that, when thus equipped, an airship may alighteither on landor water. When an airship is floating on water, supported by suchwheels, the effect of waves will be to cause the various wheels to riseand fall with the/wave motion, but each wheel can transmit to thestructure of the airship nogreater stress than is de termined by theforce of the spring or other device which holds it downward. At the sametime, the airship is supported at such elevation above the water surfacethat the fragile envelope of the airship escapes the destructive forceof the waves. Without such a resilient means of support, even smallwaves would produce in the structure of an airship stresses far greaterthan airships can withstand as at present designed or, if designed turewould probably have to be so increased the patent shall cover spring 9as to be prohibitive.

With airships thus provided with alighting wheels, the cost anddifficulty of obtaining suitable mooring stations will be greatlyreduced. Bays, rivers and lakes having suitable area and protection fromthe wind may be used as intermediate and terminal stations, or if thereexists no such body of water in a locality where a station is desired, adike canbe built around a swamp or low lying piece of ground and anartificial pond created at much less cost than would be en- .5 counteredin the purchase and leveling of an equal area of ground, free fromwater, as would be required for the manipulation of airships accordingto present methods of operation. 0

In the practical application of the invention thus set forth, variousdevices may be employed in substitution for those which are herein shownas illustrating the principles involved; and variations may be made inmany respects without departing from the scope of the invention. 7 It isintended that by suitable expression in the appended claims whateverfeatures of patentable novelty exist in the invention disclosed.

In the accompanying drawings, which are somewhat diagrammatic:

Fig. 1 is a side elevation of an airship equippedwith alighting wheels;

Fig. 2 is a side elevation of a portion of same to a larger scale andshows an alight ing wheel in its lowered and raised positions;

. Fig. 3 is a cross sectional view on line 3-3 of Figs. 1 and 2;

Fig. t shows the alighting wheel on a still larger scale with means forproviding resiliency, being a longitudinal section through one of thepockets;

r Fig. 5 is an end elevation of the same; and

Fig. 6 is a sectional View of a wheel adapted for alighting on both landand water.

In Fig. 1, the airship 1, with its power car 2 is shown supported bywheels 3 on a ground surface. These wheels are distributed along thelength of the ship, and are in rows, one at each side, as seen in Fig.3.

In Fig. 2 a wheel is shownin its lowered position, when the ship issupported by arms 4, and in raised position at 8, when the wheel isretracted within pocket 5, within the envelope 6 of the airship, as whenin flight.

Figs. 4 and 5 on a larger scale show the which holds the wheel withapproxconstant force. in a downward position, the stop 7 preventing itbeing pulled downward further than is desirable. The spring and stopcooperate to set the arm 4 in an obliquely, trailing position so that itcan both transmit weight to the ground, and yield to the rear and upwardon encounterimately V rope 10 passing ing an obstacle when runningforward. The spring is shown attached to the arm 4 by a around a sheave11 supported by a bracket 18 attached to a cross beam 15 forming part oftheframework. The latter, as illustrated, is so positioned with respectto both the axle 8 and the short arm of arm or lever 4, that theperpendicular distance from the axle or fulcrum 8 to the line of therope 10 is substantially the same at both of the illustrated limits ofmovement. This makes it possible, with a suitably chosen spring 9, tomaintain a constant limit for the supporting effect of the wheel on theairship no matter whether the wheel is in its lowest position, as shownin full lines, or in its high dotted position; and this is alsoapproximately true of any intermediate position. This is obviousmathematically upon computing a moment equation about the axle 8, andnoting that the moment arm from axle 8 to the line of the verticalthrust or supporting force acting vertically through the wheel varies inproportion to the change in the spring strength as the latter iselongated or shortened by the swing of the lever or arm 4.

Since these elements vary proportionally,

and the moment arm from axle 8 to the force acting along the rope 10remains ap roximately constant, it must follow that the remainingelement of the moment equation, namely, the supporting force or verticalthrust at the wheel, must also be constant. Accordingly the inventionenables the limit of supporting effect of each wheel to be predeterminedand to be maintained constant. Until this limit is reached the wheeloccupies the full line position illustrated; and the total pull of thespring is resisted either at the stop 7 or at the ground, or in part ateach, as the case may be; but when this limit is reached the wheel isswung upward about the axle 8; That is, when the weight of the shiprests on the wheel too heavily the sprin yields; the other wheels take uthe loac, the ship first settling lower if tiey are not already touchingground; and the load is thus distributed among them all. The springskeep each single wheel 3 extended so as to carry its full part of theload, and to prevent it from transmitting undue stress to its part ofthe frame. Various other means may be employed for accomplishing thesame result. The axle 8 about which arm 4 rotates to position 4 issupported by a bracket 19 attached to a beam 14 which is part of thestructure of the airship. There is shown a hook 12, attached by rope 13to the structure, for holding the wheel in its retracted position 3. Forwithdrawing the wheel into the envelope a rope 13 maybe provided as acontinuation of rope 13, around a sheave 12, which may be operated fromany convenient place above in the body of the ship.

In Fig. 6, the wheel?) is shown with a tread 16 adapted for running on agroundsurface,

and with a water-tight aircompartment 17 which provides buoyancy whenfloating on water.

vVhen the invention is applied to a lighterthan-air ship which isheavier with its load than the air it displaces, the ship may haveintegral air-planes to carry the excess weight in flight and thesewheels will carry on land the amount by which the weight of ship onceeds the buoyant force.

lWhat we claim is:

1. The combination, with an airship containing lighter-than-air gas, ofa multiplicity of landing supports therefor distributed fore and aftalong its underside; said supports each comprising a ground engagingmember mounted on and extensible from the frame of the ship and adaptedto yield toward it at substantially constant pressure upon contact withthe ground; a stop arranged to limit the travel of said member from theframe; a spring having operating connection with said member andanchored to a rigid part of the frame in position for holding saidmember against said stop with a pressure suflicient tor the said memberto support a limited portion of the weight of the airship withoutyielding; the mounting of said member and its spring being adapted forsaid member to yield when the ground pressure upon it on ceeds saidlimit.

2. In an airship containing lighter-thanair gas, and having amultiplicity of ground engaging supports distributed over and a-ttachedto the lower portion of said airship, means for distributing the landingstress of the airship among the several supports comprising, as a partof each said support, a lever having a ground-engaging end, a spring,and connectionsbetween the lever, the spring and the body of the airshipwhereby, upon sustaining a ground pressure of predetermined amount thesupport yields toward the body of the ship, and the said connections arearranged to provide for said pressure to be at a certain springposition, with there after during the yielding such little increase ofresistance to ground pressure as to let the ship drop until increasedproportion of ground pressure results on other supports.

3. The combination, with an airship containing lighter-than'air gas, ofa multiplicity of yielding supports distributed fore and aft over theunderside of the ship each comprising a ground-engaging member, a springfor said member, and connections between the member, spring and theframe of the airship; each yielding support having a ship-supportingstrength commensurate with the landing stresses arising from theparticular portion of the ship where the particular suport is located,and each yielding support eing constructed, mounted on and connected tothe ship so that for landing stresses, higher ground pressure about saidwhereby the spring, acting upon the ground member through said element,holds said member in repose until a predeterminable load is carried bysaid member and then permits said member to yield without further reposewhen said load is exceeded notwithstanding that the load remainssubstantially at said predetermined value at yielding is initiated.

5. Supporting means comprising a ground engaging member adapted to yieldtoward the thing supported, and means for maintaining constant thepressure of said member on the ground, during its yielding, irrespectiveof its degree of yield toward the thing supported, comprising a pivotedsupport for said member; means applying force to said member to opposeits yielding and means interposed between the last said means and themember whereby the moment of said opposing force about the pivot of thesupport counterbalances the moment of said pivot during the which saidyielding of the member.

6. Supporting means for an airship comprising a ground engaging wheel; alever, carrying the wheel and fulcrumed on the airship so as to permitthe wheel to move toward it; and spring means secured to the airship andhaving connection with said lever; and means cont-rolling theapplication of the spring force whereby the moment of resist ance at theend of yielding is approximately the same as at its beginning.

7. Supporting means for an airship comprising a lever fulcrumed ontheairship and having a yieldable connection therewith including aspring, and a wheel mounted on said lever in ground engaging positionand movable therewith about the fulcrum toward the airship; and guidingmeans for said yieldable connection providingfor change of the springforce substantially inproportion to the change in the horizontalcomponent of the distance between said fulcrum and the wheel.

8. Supporting means for an airship comprising a ground engaging wheel; alever carrying said wheel and being fulcrumed to permit the Wheel tomove toward the airship; a spring force, acting on said lever; and meanswhereby the moment arm of said spring about said fulcrum remainsapproximately constant during the turning of the lever; said springforce varying in proportion to the moment arm of the force transmittedbythe wheel, whereby thelatter force is maintained substantially constantduring movement of the wheel toward the airship.

9. Supporting means comprising a ground engaging member adapted to yieldtoward the thing supported; force exerting means attached to the thingsupported,having connection with said member; and guiding means for saidconnection whereby the force exerted by the force exerting means on themember increases in proportion as the momentarm of the ground pressureon the said member increases during the yielding.

10. Supporting means comprising a ground engaging member adapted toyield toward the thing supported; a lever pivoted intermediate of itsends on the thing supported and carrying said member on one of its arms;a spring attached to the thing supported having connection with theother arm of said lever and adapted to yield at a predetermined pressureupon the member; and guiding means for said spring connection whereby asthe lever swings the said predetermined pressure is maintained.

11. Supporting means comprisin a ground engaging member adapted to yie dtoward the thing supported; a lever pivoted intermediate of its ends onthe thing supported and carrying said member on one of its arms; aspring attached to the thing supported having connection with the otherarm of said lever and adapted to yield at a predetern'iined pressureupon the member; and guiding means for said spring connection whereby asthe lever swings the angle between said connection and the lever remainssubstantially unchanged.

Signed at New York, N. Y., this first day of July, 1921.

WILFRID V. N. POWELSON. \VARREN TRAVELL.

